/Engine/Plugins/Animation/ControlRig/Source/ControlRig/Public/Rigs/RigHierarchy.h
Sets a control's preferred rotator (local transform rotation)
void SetControlPreferredRotator ( [FRigControlElement](API\Plugins\ControlRig\Rigs\FRigControlElement) * InControlElement, const FRotator & InRotator, bool bInitial, bool bFixEulerFlips )